1. Field of the Invention
The present invention relates generally to a telecommunications system and method for improved routing of a subscriber's incoming calls, particularly to a telecommunications system and method for keeping track of the location of a subscriber within the telecommunications system and routing an incoming call for that subscriber to that location, and, more particularly, to a system and method for routing a cellular subscriber's incoming call to the non-cellular number offering the best-chance for locating the subscriber.
2. Background and Objects of the Invention
The evolution of wireless communication over the past century, since Guglielmo Marconi's 1897 demonstration of radio's ability to provide continuous contact with ships sailing the English Channel, has been remarkable. Since Marconi's discovery, new wireline and wireless communication methods, services and standards have been adopted by people throughout the world. This evolution has been accelerating, particularly over the last ten years, during which the mobile radio communications industry has grown by orders of magnitude, fueled by numerous technological advances that have made portable radio equipment smaller, cheaper and more reliable. The exponential growth of mobile telephony will continue to rise in the coming decades as well, as this wireless network interacts with and eventually overtakes the existing wireline networks.
Currently, there exist services, such as a Single Personal Number (SPN) service, where alternative numbers are tried when attempts to locate a cellular subscriber within a network fail. For example, if the subscriber does not answer (or is unreachable) on their cellular phone, the telecommunications system then forwards the call through the Public Switched Telephone Network (PSTN) or the Integrated Service Digital Network (ISDN) to an alternate non-cellular number for that subscriber, e.g., their residence or work number, in a further effort to contact them. Similarly, a further failure to contact the subscriber may initiate a call to a third number, e.g., voice mail, and so forth. For example, a particular series of numbers used by an SPN system may indicate a series of attempts at (1) the subscriber's mobile phone number, (2) then the subscriber's work number, and (3) finally the subscriber's voice mail number at work.
The problem with such in seriatim SPN listings, however, is their lack of flexibility and adaptation to actual uses. For example, after the subscriber has gone home for the evening, the above fixed SPN sequence of numbers, for use on contacting the subscriber at work, is no longer useful for reaching the subscriber. Instead, the call may be forwarded to voice mail at work, and the subscriber may not learn about the call for days. It is, accordingly, readily apparent that a more flexible approach is necessary to best route a given incoming call in a cellular system to a given unanswering subscriber at their most likely current cellular or non-cellular telephone number or location, which may vary during the day.
It is, accordingly, an object of the present invention to route incoming calls to unanswering cellular subscribers in an SPN service utilizing a flexible protocol.
It is a further object of the present invention to keep track of the last known location of the SPN subscriber within the telecommunications system and route the incoming calls to those numbers associated with the last known location which have the best chance of reaching the subscriber pursuant to the flexible protocol.